1. Field of the Invention
The invention relates to a method for scanning neighbor base stations of a communication apparatus, and more particularly to a method for scanning of neighbor base stations of a communication apparatus according to a prioritized order.
2. Description of the Related Art
Orthogonal frequency division multiplexing (OFDM) is an efficient modulation scheme for signal transmission over frequency-selective channels. In OFDM, a wide bandwidth is divided into multiple narrow-band sub-carriers, which are arranged to be orthogonal with each other. The signals modulated on the sub-carriers are transmitted in parallel. Orthogonal frequency division multiple access (OFDMA) is one way of using the basic format of OFDM to support multiple access for multiple subscribers. In OFDMA, multiple subscribers simultaneously use different sub-carriers, in a fashion similar to frequency division multiple access (FDMA).
A heterogeneous network, including at least two different cells from macro, micro, pico, and femto cells, is designed to fulfill the requirement of future communication (i.e. 4G) system. In IEEE 802.16-like system, Hierarchical Cell Structure (HCS) has been proposed, and HCS is one of the promising techniques for heterogeneous network deployment. FIG. 1 shows an exemplary communication network, constructed by cells in the hierarchical cell structure. As shown in FIG. 1, hierarchical cell structure is a multi-layered network structure with cells and base stations of overlapped geographic coverage, in which base stations within a same layer have common associations and services, and may be configured independently from the base stations in other layers. Such kind of network deployment is called a heterogeneous network deployment.
However, the heterogeneous network deployment, to a certain extent, increases difficulties when exchanging neighbor cell information between the base stations and the mobile stations due to the configuration differences between the base stations. Thus, a novel scheme for managing the neighbor cell information to further improve system performance is highly required.